There's an odd synchronicity between two superficially dissimilar new books: one, by Paul Hawken and his coauthors, is about the need to turn back the devastating harm that's been done to the environment; the other, by Tim Berners-Lee, is about his adventures creating the World Wide Web. Both capture the passion with which each author has tackled a huge challenge.

The authors of Natural Capitalism: Creating the Next Industrial Revolution argue that unless we redefine capitalism so that it means more than just "accumulated wealth in the form of investments, factories, and equipment" and includes human capital (labor, intelligence, culture, organization), financial capital (cash, investments, monetary instruments), manufactured capital (infrastructure, machines, tools, and factories), and natural capital (resources, living systems, and services such as flood management that are provided by living systems like forests), we'll nearly deplete our 3.8-billion-year store of natural capital by the end of the next century. They offer examples of companies that have embraced this redefinition of capitalism and, as a result, have prospered.

Redefining business is also at the heart of Berners-Lee's vision in Weaving the Web: The Original Design and Ultimate Destiny of the World Wide Web by Its Inventor. Instead of packing his book with techno-jargon, Berners-Lee decided to tell a very personal story of how he created the World Wide Web (which, after all, had its roots in the work he did in his spare time while employed at CERN, the famous European Laboratory for Particle Physics in Geneva). Berners-Lee saw the Web as a medium in which people could not only browse but easily create their own material as well. The original World Wide Web program, he writes, "opened with an almost blank page, ready for the jottings of the user." The "dream of people-to-people communication...must be possible for groups of all sizes, interacting electronically with as much ease as they do now in person."

Berners-Lee is not totally convincing when he explains why he decided not to start the Web as a business. Making it a commercial venture would have been "by no means a guarantee of future riches," he writes, and was a considerable financial risk. He says that starting a company might have inspired potential competitors to do the same, quashing the collaboration among different players that was needed to build the Web. Maybe, but you can't help feeling his pain as he describes being introduced on CNBC as the man who "actually invented the World Wide Web." The interviewer then asked, "Tell us, exactly how rich are you?" Though he doesn't say so, it's clear that "not very" would have been an appropriate answer. He's been reluctant to go on live TV since.

Still, his message that the Web was brought about by a group of people with vastly varying agendas is heartening for both his mission and Hawken's. "The experience of seeing the Web take off by the grassroots effort of thousands," he writes, "gives me tremendous hope that if we have the individual will, we can collectively make of our world what we want." That might sound too lofty for belief, but it works here because Berners-Lee was able to bring his vision of the Web to life.

When I get older

Age Power by Ken Dychtwald (Tarcher/Putnam, 1999)

Agequake by Paul Wallace (Nicholas Brealey, 1999)

In 1980, Landon Y. Jones wrote a wonderful book (now out of print) called Great Expectations: America and the Baby Boom Generation. In it he warned companies that those who live by the baby boom shall die by the baby boom.

It's coming true now. Boomers are getting old. Unless marketers keep up with the demands of these now thirtyfive-to-fiftysomethings, they're toast.

Enter Ken Dychtwald and Paul Wallace, each with his own book to warn us how the world is changing. "In the year 2000, approximately 76 million Americans will be past the age of 50," Dychtwald writes. "This is exactly the number of Americans that there were--in total--in 1900. It's as though the American nation is giving birth to a 'senior nation.' "

Dychtwald has been focusing on the issue of aging in America for some time. He offers compelling evidence that smart businesspeople are already gearing up to take advantage of the growing dominance of the elderly.